High speed data communication in a circuit channel requires less noise. However, each pulse/bit sent over the channel may cause a series of reflections, and those reflections sum to cause jitter on later pulse/bits. The duration of the reflections may be highly channel dependent, but a typical fully buffered dual in-line memory module (FB-DIMM) channel architecture may result in significant ringing for between 5 and 10 ns after an edge. Thus, there is a desire to minimize intersymbol interference (ISI) due to jitter.
Channels can be characterized using their S-parameter representations. A typical channel will show increasing loss as the frequency increases, resulting in a degradation of the amplitude and an increase in the amount of energy present after the main cursor has passed.